Vehicle does not heat up properly. Temperature gauge does not register correctly, and the heating system does not heat up to warm the car. It is believed the hoses are not getting any pressure, but yet there are no leakages anywhere. The car does not overheat. How do we get the heating system to work? Also, it is a manual transmission and it bogs down while changing gears while driving. What causes these problems? PLEASE HELP ME!!!!!!!